GREEN BAY, Wis. (AP) — Vice President Joe Biden stayed with traditional themes Sunday during a campaign stop in Green Bay, saying Democrats are fighting for the middle class while Republicans try deceptively to blame the economic downturn on President Barack Obama.

"There is not a single doubt in my mind that we're on our way to rebuilding this country stronger than it was before this recession," Biden said. "We're on our way to rebuilding the middle class, more vibrant than it was before. Because I know given half a chance, the American people never, ever, ever let the country down."

The campaign stop was part of the Obama-Biden campaign's "Road to Charlotte" tour, leading up to the Democratic National Convention that starts Tuesday in North Carolina.

Biden said Republican presidential candidate Mitt Romney and running mate Paul Ryan talk about restoring America, but he said that would mean restoring the same economic policies that have already failed. Romney and Ryan call their plan new, but it's actually a tired strategy that would benefit the wealthy at the expense of the middle class, he said.

"Not only is it not new, it's not fair. It's simply not right," Biden said. "It will not grow the economy. How do I know? They tried it before. It didn't work before."

Biden spoke at the National Railroad Museum in Brown County. Obama and Biden won the county and surrounding areas in 2008, but those regions went to Republican Gov. Scott Walker in 2010 and again in his June recall election win.

A few hours before the vice president spoke, the Romney campaign released a statement criticizing Obama and Biden as failing to offer solutions.

"Wisconsinites are fed up with the debt, doubt and decline under the Obama administration," Romney campaign spokesman Ben Sparks said. "... Wisconsin families are now looking to Gov. Romney and Paul Ryan, who have a plan that will strengthen the middle class, help businesses grow and turn our economy around."

Rob Aragon, 31, of Green Bay, is among the small percentage of voters who remain undecided. He said he was impressed by Romney's and Ryan's speeches at the Republican National Convention, but he also wanted to hear what Biden had to say. He said told the Green Bay Press Gazette (http://gbpg.net/TaYuYh ) the decision comes down to which party has the stronger economic plan.

"Social issues, out the door for me," Aragon said. "I need to have a job to care about any of those things."